Lets face it, with the release of a new expansion along with new dungeons there are going to be bad pugs. This could range from people not knowing the fights, to breaking sheeps for no apparent reason what so ever. However, even the worst pugs can be fixed with a few simple techniques.

#1: Read up on the new content.
Now, you might not always have to explain fights, but having a solid understanding of the fight's various mechanics and ability's will come in handy in almost all pugs. Even if everyone in the group may know the fight, you may have studied up on it and know an easier or more effective way of handling the situation.
For Example: If a boss has a raid-wide aoe spell that can be counteracted by moving him in a specific manner (Karsh Steelbender for example) and the group your in doesnt know the particular way you do, tell them! If it makes the encounter easier on the group then everyone will be happy!

#2: Always be polite.
As hard as this may be for some of us, it is a necessity. If your rude and obnoxious to your pug then chances are, they will grow to dislike you, making that vote to kick button all the more feasible. If the group isn't up to par with your standards or may be making simple mistakes, don't reprimand them harshly by using hateful speech or harsh words, calmly explain the situation and what can be done to improve it.
For Example: "You noobs, why would you stand in the fire, FIRE IS NOT A BUFF, move out of the fire or uninstall WoW. you fail at life and at this game." What was accomplished by that reaction to a mistake? Four more people who want nothing to do with you.
"Hey guys, Instead of tanking the boss right there could you move him away from us a bit? He's doing a lot of aoe damage and its causing a strain on the heals."
By being calm and polite you've identified the problem and combated it in a respectable manner.
However the is always the chance that the group is less than pleased with your advice. We've all been there, giving advice and having it shoved aside. If this problem happens to arise I know that some players would get mad and most likely throw a fit. Well Be reasonable, maybe they truly feel that they know best, if so, attempt to kick them. If a kick isn't passed, simply leave and re-queue.

#3: Nobody like a ninja.
Ninja looting is frowned upon by the WoW society so you probably shouldn't do it. Everyone has been ninja'd at some point, and it's never fun. Weather it be that mount you've been trying to get for weeks or a new piece of gear that you need. Everyone has their fair share at a roll (as long as they can actually benefit from it). You wouldn't go up to someone who's just won the lottery and take their ticket now would you? Well, I certainly hope not. The same rule applies here. Everyone who can use the item should get a fair roll on it, no questions asked.

#4: Understand and use CC!
As a mage, I can not stress the use of Crowd control kill orders. Think about it like this, If there are 5 enemies who are doing damage to the tank and maybe aoe to the ranged and melee, healers are more than likely going to run out of mana, resulting in a wipe. If there were only one or two enemies able to attack the group could focus down the remaining targets one at a time, which is much less stress on the healers. The most widely accepted system for marking targets is as follows.
Skull: Main target, all DPS focus this one down after CC's are in place.
X: Second after the skull, same as above.
Moon: Sheep, AKA Polymorph. Sheep are your friends, please don't attack these until told to!
Square: Frost Trap.
Triangle: Hex.
Diamond: Mind Control.
Circle: I use this to mark Bind elemental, but it varies.
Kill order goes from Skull, to X, To square, To Triangle, To Moon, To Circle, To diamond. Obviously you wont have seven targets CC'ed in a heroic pug, so use this to accommodate your group. For instance say you have a Sheep, Hex and an MC. Kill Skull, Kill X, Take down the Hex, then the Sheep, finally the MC.
The use of crowd control can and will save your pug time, repair bills, and frustration.

#5: Don't be afraid to ask questions.
If you don't know the fight, A: you didn't read rule number one. B: you should ask for the run down on it.
Most wipes I've come across are due to lack of understanding. Asking for someone to explain the fight is not too much to ask, in fact, the thirty seconds it takes to explain a boss encounter can save a group hours in wipes. If necessary, ask to take a short break, so you and any others in a group may youtube or google the strategy for the fight. Trust me on this one, it saves time, and a lot of gold in repairs.


My recommendations on sites to use:
WoWWiki.com
YouTube.com
MMO-Champion.com
Wowhead.com

Thanks for reading my guide on how to be Pug ready! I hope this has been very resourceful for you. If you have any questions or comments please feel free to add them below!